(a) Field
The invention relates to a sputtering device.
(b) Description of the Related Art
As a personal computer, a television or the like has been lightened and slimmed, a display device used in the personal computer, the television or the like should be commensurately lightened and slimmed. In order to make the display device lighter and slimmer, a flat panel display such as a liquid crystal display has been developed to replace a cathode ray tube (“CRT”) display of a conventional display device.
The liquid crystal display applies an electric field to a liquid crystal material having dielectric anisotropy which is between two substrates. The liquid crystal display controls the intensity of the electric field to control a quantity of light which is transmitted to one or both of the substrates, thereby acquiring a desired image signal. Since the liquid crystal display may be a portable flat panel display, a thin film transistor liquid crystal display (“TFT LCD”) using a thin film transistor (“TFT”) as a switching element is frequently used as the liquid crystal display.
In manufacturing a liquid crystal display, a sputtering device is one of many manufacturing devices used when a thin film (for example, a metal thin film) is deposited on a substrate for a semiconductor device or on a substrate for a liquid crystal display. The sputtering device is treated as a critical device when the semiconductor device or the liquid crystal display is manufactured.
In the sputtering device, the thin film is generally deposited by the following method. When a voltage is applied in a vacuum state and argon (Ar) gas or oxygen (O2) gas is injected, ions collide with a target while the argon (Ar) gas or the oxygen (O2) gas is ionized. In this case, atoms are discharged from the target and the discharged atoms are attached to the substrate for a semiconductor device or to the substrate for a liquid crystal display, to form the thin film.
A sputtering process may form a thin film at a relatively low temperature as compared to a chemical vapor deposition (“CVD”) process which is performed at a relatively high temperature, and may form a thin film in a relatively short time and in a simple structure such that the thin film is widely used when the semiconductor device or the liquid crystal display is manufactured.
However, as a size of the substrate increases, uniformity of the thin film may undesirably deteriorate. Therefore, there remains a need for an improved sputtering device which provides a uniform thin film on a substrate even as a size of the substrate increases.